It is an excuse.
You don't need to polish something into a shiny gem of perfection before showing it to people; and you certainly don't need to get defensive about feedback (which in this case wasn't harsh at all); especially not for something out in the public that various people are already using.
Iterative feedback and improvement can only happen if you get feedback.
It's tempting to say that something isn't quite ready for others to see yet, it needs a bit more polish, and bit more internal beta testing, a bit more perfecting before you show it people.
...but I'd say that most cases, it's not the right attitude to encourage (although there are some very specific cases; like product launches where a botched launch has long term negative ramifications).
Have a think about what you wrote there.
You're endorsing self defensive attitude of perfectionism that you're criticizing.